RetroKnight

Hello all, I recently managed to install a subwoofer into my Skoda Fabia 2023 - took me about a week (had 0 knowledge of how to do anything) but eventually managed to get it done! Below is an account of what I had to do to get around a lot of things. I hope this might be useful for someone in the future so they don't have to do things with no guidance of this exact car model. 1) Power supply My subwoofer was a 10 inch one demanding 750 Watts of power. In theory, getting power from the battery to the subwoofer is easy: hole through the grommet in the firewall and under the trimmings.. right? No. There is no grommet on the passenger footwell. I checked. Many many times. I was on the verge of completely giving up the install after searching for about 15 hours on both sides of the firewall (yes I removed the battery and looked, yes I looked under the scuttle trim, yes I followed the cables but there was no grommet. I didn't want to drill) But then I saw a grommet on the outside of the A column after opening the passenger side door - I found an opening on the left side of the passenger footwell (behind the trimming of the bonnet lever) and managed to get the cable from the inside to the outside. After, I routed it behind the door hinge and into the rubber trimming running along the side. After opening the bonnet, I saw it poking through the top right side and pulled it. Success! After a bit of tinkering with the fusebox cover, I managed to get the power connected to the ring connector on the positive terminal within the fusebox itself. Right now how do I wire this to the boot? Relatively simple actually. The trimming on the front side of the car was easier to poke the wire through but the rear seats felt like they were fused into the rear trimming. I basically had to pry open the trimming from the edge and thread it through but how do I get it to the boot? Hmm, I tried lifting the trimming inside the boot but this thing was so stiff I couldn't get a finger underneath. Ok, why don't I just thread the wire through the inside of the seatbelt trimming and try and fish it out from the other side under the trimming adjacent to the seat? Yep. After about 2 hours of essentially fishing and praying the wire was going in the correct place, I managed to hook it from inside the boot and pull it through. Cool. The fuse was in place next to the battery. Power was basically done. 😁 2) Ground cable In theory this was the simplest step. But I couldn't find a bolt in the chassis for about 3 hours... I was trying to remove the seats but unlike the videos online, my rear seats didn't BUDGE. I then saw that apparently they're not meant to come out? Fine. I checked inside the left side trimming as well but nothing. But then out of rage I checked the spare wheel spot under the boot again and stuck my entire head inside until I saw below the hatch trimming and behold! There was a bolt. Sandpapered it down and had to buy a few nuts (M5 worked) and checked the grounding on the multimeter. Solid. 3) Audio cables Ok this was the interesting part. I read that high and low-level inputs were both valid, with RCA cables and low-level being favoured as the easier option. Well I didn't know how to remove the head unit and given the proportionally higher resistance I faced on all the other parts, I didn't bother researching how easily I could've pulled it off. High-level inputs it is! I read that I need to find the speaker cables in the loom, so I cut open the loom fabric and thought I would find only a few cables. Nah. There's about 15 of them in this loom. Hmm.. Well the speaker cables are usually positive and negative pairs.. so they should be twisted together! Cut the insulation and tested the sound with the multimeter and saw it increased with volume and bass drops. Ok cool. Military spliced the wires (bit difficult with the lack of room to work with in this loom) and taped it up. Ok cool, that should be everything!! I quickly spliced the positive and negative wires (after testing with multimeter) and wanted to test the subwoofer. It's been about 6 days of work at this point (yes I'm a bit slow) so I was desperate to hear something. It doesn't turn on!!!!! 4) REM cable It seems the other cable in the packet was also required... remote cable to connect to the ignition live. So the subwoofer knows when to turn on. Hmm should be easy right? Found the fusebox behind the driver side glovebox. Okay at least that was accessible.. Have to find a fuse which starts up with the car, found the windscreen washing system one. Lovely. Went and got a fuse piggyback and a 5 amp fuse. Plugged it in and tested the soldered cable --> seems to be working... let's put the wire on the amp and see if it turns on... nothing. ??? The wire is 11volts.. goes up to 13 when the engine is on.. still nothing. ?? Checked what the voltage was when it was actually on the amp screw: 5 volts?? Hmm. Let's change the fuse slot, rear window heating sounds good, maybe that won't throttle the voltage. Yep. Worked well. Wired it the same way as the power. Found out the fishing technique works much better when you shove your fingers down the seat from the rear seat side instead of the boot. Not sure how useful this is but very fun project overall :)